Process for breaking petroleum emulsions



Patented Dec. 31, 1935 UNITED fiTATES PROCESS FOR BREAKING PETROLEUMZ EMUL Melvin De Groote, St.

Webster Groves, an

mond Heights, Mo., as pany, Webster Groves,

ouri

SIONS Louis, Bernhard Keiser,

d Arthur F. WirteL Bichsignors to Tretolite Com- Mo., a corporation of No Drawing. Application December 31, 1934, Serial No. 760,033

6 Claims.

This invention relates to the treatment of emulsions of mineral oil and water, such as petroleum emulsions, for the purpose of separating the oil from the water.

Petroleum emulsions are of the water-in-oil typ and comprise fine droplets of naturally-occurring waters or brines, dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion. They are obtained from producing wells and from the bottom of oil storage tanks, and are commonly referred to as cut oil, roily oil, emulsified oil and bottom settlings".

The object of our invention is to provide a novel and inexpensive process for separating emulsions of the character referred to into their component parts of oil and water or brine.

Briefly described, our process consists in subjecting a petroleum emulsion of the water-in-oil' type to the action of a treating agent or demulsifying agent of the kind hereinafter described, thereby causing the emulsion to break down and separate into its component parts of oil and water or brine, when the emulsion is permitted to remain ina quiescent state after treatment, or is subjected to other equivalent separatory procedures.

The treating agent used in our process consists of an unpolymerized keto fatty body or bodies. It is well known that fatty acids or fatty bodies can be subjected to chemical treatment so as to yield keto fatty acids, that is, fatty acids in which a ketonic group (a carbonyl group) is present. One example is the conversion of ricinoleic acid into ketohydroxystearic acid. (See Lewkowitsch Chemical Technology of Oils, Fats and Waxes, Gthedition, volume 1, page 242.) In a general way, the manufacture of such ketonic acids is dependent upon the treatment of an unsaturated fatty bcdy or fatty acid, such as ricinoleic acid, oleic acid, or the like, with a halogen, such as bromine, so as to form a halogen addition product, for example, ricinoleic acid dibromide, which. is then converted into ricinstearolic acid. Ricinstearolic acid, on treatment with sulfuric acid, yields ketohydroxystearic acid.

In our co-pending application for patent Serial No. 760,031, filed December 31, 1934, we have disclosed the use of poly keto fatty acids or the salts or esters thereof for breaking oil field emulsions. In a general manner we have found that frequently the poly keto fatty acid bodies are more effective for breaking the majority of emulsions than the unpolymerized keto fatty acid bodies. This is true to the same general extent that,

broadly speaking, polyricinoleic acids are more efiective demulsifying reagents than ricinoleic acid. However, there are certain emulsions on which the unpolymerized keto fatty acid bodies, which will be referred to more simply as keto fatty acid bodies, are more effective than the polymerized keto fatty acid bodies. The present process is concerned with the use of keto fatty,

1934. Said aforementioned application for patent.

discloses the oxidation of highly unsaturated fatty bodies having a relatively high iodine number, above 120, for example, so as to produce unsaturated, hydroxylated fatty bodies.

In our co-pending application for patent Serial No. 760,031, filed December 31, 1934, we have described a new composition of matter consisting of the poly keto fatty acid bodies. These poly keto fattyacid bodies may beobtained by the esteriflcation or polymerization or condensation of a keto fatty acid with another fatty acid molecule, which need not contain a ketone group. In said aforementioned application for patent describing these new compositions of matter, there is also disclosed a method for producing poly keto fatty acids directly without first forming the unpolymerized keto fatty acids. It would appear'at least theoretically possible to decompose such poly keto fatty acid bodies and perhaps separate from the resultant mixture unpolymerized keto fatty acid bodies. Thus far, however, we-have been unable to accomplish this hydrolysis and separation,

but this is immaterial because the keto fatty acids may be produced in the manner previously described.

We are fully aware place in a fatty molecule.

that migration may take For instance, that the formation of stearolactone from hydroxystearic' acid appears to depend on the migration of the alcoholiform hydroxyL- We are also aware that. in the case of the-common non-fatty ketonic acid, aceto-acetic acid, that certain reactions are known to take place which suggest that acetoacetic acid may, a far as these reactions are con-- cemed, react more as an aldehyde or as an aldehyde acid than as a ketonic acid. Such wandering of a hydrogen atom and change in position of a double bond, is referred to as keto-enolic tautomerism (Bernthsen Textbook of Organic Chemistry, 2nd edition, 1931, page 231). We believe that this or a comparable change may take place in these ketonic fatty acids or bodies previously described. Possibly in regard to some reactions employed in identification, these keto acids or salts or esters thereof act more as if they were aldehydic acids or esters or salts thereof. In other words, if these ketonic acid bodies are to be used in a mixture where aldehydic acids would be incompatible, it is also likely that these ketonic acids or their salts or their esters may be incompatible, for the reason that they really may be aldehydic acid bodies. It is to be noted that the reagents of the kind employed for determining the presence of the carbonyl group in ketones also usually detect the presence of the carbonyl group in aldehydes. It is to be understood that in the claims where the products are characterized by the presence of ketonic radical, that such acids might ultimately prove to be aldehydic acids, or at least convertible under certain conditions of use, or else under certain conditions of identification, possibly they become converted into aldehydic acids, and it is not intended that the word ketonic or keto be interpreted as excluding the meaning of aldehydic in the sense previously described or discussed, i. e., that both have the carbonyl (CO) radical present, and their ultimate composition in carbon atoms, hydrogen atoms, and oxygen atoms, is identical.

It is understood, of course, that these keto fatty acids or their esters may be converted into salts or into esters in the manner generally employed for the manufacture of salts and esters. However, it should be borne in mind that saponification of the kind which would decompose or destroy the carbonyl radical cannot be employed. In such instances where it is desirable to eliminate the residual acidity, it is best accomplished by means of a relatively weak base, such as triethanolamine, or it may be accomplished by means of a stronger base, such as ammonium hydroxide or caustic soda, provided the neutralization is conducted with care. In some instances it is desirable to mix an alcohol, particularly a po yhydric alcohol, such as glycerine or ethylene lycol with a keto fatty acid body and then heat so as to eliminate the carboxylic hydrogen. In a y event, the ketonic bodies may be converted into any suitable form by means of conventional reactions, provided that the material is not decomposed to destroy the carbonyl radical.

Our preferred reagent consists of unneutralized ketohydroxystearic acid obtained from ricinoleic acid in the manner previously described. For the sake of convenience we prefer to dilute the ketohydroxystearic acid with 50%, by weight, of a solvent composed of equal volumes of methyl alcohol and solvent naphtha.

The use of demulsifying agents consisting of various sulfo acids, or carboxy acids, or compounds having both a sulfo group and a carboxyl group, is well known in the treatment of waterin-oil emulsions. In the use of conventional demulsifying agents it is the common practice to use them, not only in the form of acids, but also in the form of salts or esters, or half salts, or half esters, or ester salts, in case of dibasic acids. The salts generally employed are the sodium salt, potassium salt, ammonium salt, calcium, magnesium, the triethanolamine salt, etc. The esters may be employed, such as the methyl ester, ethyl ester, propyl ester, butyl ester, amyl ester, hexyl ester, cetyl ester, etc. Aromatic or cyclic esters may be employed. What has been said in regard to the use of conventional demulsifying agents 5 applies also to the materials employed as the demulsifying agent of our process, with the limitation that such materials are generally monobaslc, although it is probable that dibasic acids, such as sulfoketostearic acid might be prepared, and w would prove to be a suitable demulsifying agent.

Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water, petroleum hydrocarbons, such as 15 gasoline, kerosene, stove oil, a coal tar product, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, 20 butyl alcohol, hexyl alcohol, octyl alcohol, etc. may be employed as diluents. Miscellaneous solvents, such as pine oil, carbon tetrachloride, sulfur dioxide, extract obtained in the refining of petroleum, etc. may be employed as diluents. 35 Similarly, the material or materials employed as the demulsifying agent of our process may be admixed with one or moreof the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone or in admixture with other suitable well known classes of demulsifying agents, such as demulsifying agents of the modified fatty acid type, the petroleum sulfonate type, the alkylated sulfo-aromatic type, etc.

It is well known that conventional demulsifying agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both oil and water solubility. Sometimes they may be used in a form which exhibits relatively 40 limited water-solubility and relatively limited oil solubility. However, since such reagents are sometimes used in a ratio of 1 to 10,000, or 1 to 20,000, or 1 to 30,000, such an apparent insolubility in oil and water is not significant, because 15 said reagents undoubtedly have solubility within the concentration employed. This same fact is true in regard to the material or materials employed as the demulsifying agent of our process.

As stated previously, it has been so common to 50 use a conventional demulsifying agent derived from an acid in the form of the acid itself, or in the form of a salt, or in the form of an ester. that the expression acid body is frequently employed to mean' the acid itself, or an ester thereof, 56 or salt thereof. The word body is herein employed in this same sense in conformity with its prior usage in the trade, and particularly in various patents of the prior art. Half salts and half esters are considered as'salts, and esters, respectively.

In practising our process a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various 65 ways or by any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent.

Having thus described our invention, what we claim as new and desire to secure by Letters Pat- 70 en 1s:

1. A process for breaking a petroleum emulsion of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent, comprising a keto fatty acid body.

agent, comprising a keto fatty acid body in the form of an acid and derived from castor oil.

5. A process for breaking a petroleum emulsion of the water-in-oil type, which consists in subjecting the emulsion to the action of ketohydroxystearic acid.

6. A process for breaking a petroleum emulsion of the water-in-oil type, which consists in subjecting the emulsion to the action of ketohydroxystearic acid with 50%, by weight, of a solvent com- 10 posed of equal volumes of benzol and ethyl alcohol.

MELVIN DE GROOTE. BERNHARD KEISER. ARTHUR F. WIRTEL. 

